san jose being a famous location for one of these towers, and those lights were expensive, and because they were so brilliant, the idea was you could just create one single artificial moon above the town and that would -- rather than putting a lot of lamps down low, and, often, when you erect the one moon, it casts terrible shadows over large swaths of town where it didn't reach so you had to do another tower and another. you know, detroit was the sort of market society with 70 separate towers to try to get every spot in town, and it worked so badly that pretty soon the towers fell down in the high winds, and they let them go. >> so the individual solution was the solution being sought after with this refinement that edison and his own competitors wanted. >> that's right. what they called to make the lights visible. it was one thing to make one massive light of many thousands of power, but it was another to break the light up into usable pieces to bring indoors. when they brought the ark light indoors, which they tried to do often in fancy balls and those things, the light made everybo